CN108871307A - The automatic direct-coupling device of Y waveguide chip based on image recognition and optical power feedback - Google Patents

Abstract

The invention is an automatic direct coupling device for a Y waveguide chip based on image recognition and optical power feedback, which belongs to the technical field of optical fiber sensing. The device mainly includes an optical path unit, an image acquisition unit, a motion execution unit, and an image processing and control unit. The image acquisition unit includes a right-angle prism, three cameras and three LEDs; the motion execution unit includes a Y waveguide fixing mechanism, an electric stage for erecting the camera, a six-dimensional electric stage for controlling the attitude of the input end, the front output end and the rear output end, and the movement controller. The image processing and control unit first adjusts the poses of the input terminal, the front output terminal and the rear output terminal according to the images collected by the camera, and then fine-tunes the coupling point according to the optical power value returned by the circulator measured by the optical power meter. The invention avoids two welding points inside the fiber optic gyroscope, simplifies the manufacturing process of the fiber optic gyroscope, reduces back reflection and polarization crosstalk introduced by fiber optic welding, and improves the measurement accuracy, service life and quality of the fiber optic gyroscope.

Description

Automatic direct coupling device for Y waveguide chip based on image recognition and optical power feedback

technical field

The invention relates to an automatic direct coupling device for a Y waveguide chip based on image recognition and optical power feedback, belonging to the technical field of optical fiber sensing.

Background technique

Integrated optics technology originated in the early 1980s. Inspired by integrated circuits, multiple optical separation devices are integrated on the same chip to reduce the volume and weight of the system and improve system reliability. After nearly 30 years of research and development, integrated optical devices have entered the stage of industrialization abroad, and representative products include light intensity modulators and Y-waveguide integrated optical devices for fiber optic gyroscopes.

Fiber optic gyroscopes are angular rate sensors based on the Sagnac effect and are one of the most important achievements in the field of fiber optic sensing. Due to its small size, large precision coverage, high reliability and other advantages, it has become an important device in inertial technology, and is widely used in various aircraft, ships, positioning and orientation, geology, oil exploration and other fields.

At present, fiber optic gyroscopes generally use broadband light sources, Y-waveguide chips and polarization-maintaining fiber ring solutions. The current mature production technology is as follows: first, the light entrance point, front light exit point, and rear light exit point of the Y waveguide chip are respectively coupled with the pigtail of the auxiliary input end, the front output end, and the rear output end. During the coupling process, by injecting light into the input end and monitoring the optical power at the output end, the coupling quality monitoring is realized. When the coupling quality meets the requirements of the fiber optic gyroscope, the coupling point is solidified; then the auxiliary pigtail and the optical fiber ring are fused using a polarization-maintaining optical fiber fusion splicer.

The problems in the aforementioned prior art are as follows: firstly, when the optical fiber ring and the auxiliary pigtail are fused, the fusion quality cannot be monitored due to the closed optical path, resulting in that the fusion point between the auxiliary pigtail and the optical fiber ring is very easy to be caused by end face reflection and Polarization cross-coupling introduces back reflection and polarization crosstalk, and at the same time introduces splicing loss, resulting in a decrease in the signal-to-noise ratio, which ultimately leads to a decrease in the accuracy of the fiber optic gyroscope; The fiber optic gyroscope is prone to breakage, which greatly reduces the life and quality of the fiber optic gyroscope. In addition, the fiber optic gyroscope needs to be connected multiple times during the production process of the fiber optic gyroscope, which makes the production process of the fiber optic gyroscope complicated and increases the production cost.

The Chinese patent application with the publication number CN 102927979A disclosed on February 13, 2013 a fiber optic gyroscope and a method for online detection of fiber coupling quality during its manufacture. Among them, in order to realize the direct butt coupling between the Y waveguide and the fiber ring, a straight waveguide is provided in the Y waveguide chip and located on both sides of the Y waveguide as an auxiliary waveguide, which can be detected by detecting the coupling quality between the pigtail and the straight waveguide. Reflects the coupling quality between the Y waveguide and the fiber ring. However, this solution has the following problems: the fiber coupling quality is heavily dependent on the processing technology of the straight waveguide. If there is a processing deviation in the straight waveguide, the coupling quality of the straight waveguide cannot accurately reflect the coupling quality of the fiber ring and the Y waveguide; this solution does not involve automatic coupling technology , the coupling accuracy is limited by the level of human operation, and the reliability is poor.

Contents of the invention

In order to solve the problem of complex production process existing in the production of fiber optic gyroscopes and further improve the measurement accuracy and optical path reliability of fiber optic gyroscopes, this invention proposes an automatic direct coupling device for Y waveguide chips based on image recognition and optical power feedback. The identification method can quickly and accurately realize the real-time measurement of the six-dimensional attitude of the Y waveguide chip and the polarization-maintaining fiber. The optical power meter feedback method can be used to obtain the optical power returned by the coupler online, and adjust the input terminal, front output terminal, and rear terminal according to the attitude information and optical power information. The position of the output end realizes precise coupling with the light entrance point, front light exit point, and rear light exit point of the Y waveguide chip.

The invention provides an automatic direct coupling device for Y-waveguide chips based on image recognition and optical power feedback, which includes an optical path unit, an image acquisition unit, a motion execution unit, and an image processing and control unit.

The optical path unit includes a Y waveguide chip to be coupled, an input end, a front output end, a rear output end and an optical fiber ring, and an optical power meter is set to measure the optical power returned by the input end.

The motion execution unit includes: a Y waveguide fixing mechanism for fixing the Y waveguide chip, a one-dimensional electric platform for the left camera, a two-dimensional electric platform for the right camera, and a three-dimensional electric platform for the rear camera, respectively controlling the input terminals , three six-dimensional electric tables for the attitude of the front output end and the rear output end, and a motion controller. The motion controller sends attitude control signals to the one-dimensional electric stage, the two-dimensional electric stage, the three-dimensional electric stage and the three six-dimensional electric stages.

The motion controller includes a programmable logic controller and a step ladder program. The motion controller adopts time-division multiplexing technology to divide the 24-axis motors of the 6 electric tables into four groups, each group controls 6 dimensions, and uses the 6-channel pulse interface of the programmable logic controller to control 6 dimensions. The stepping ladder program includes instruction receiving, instruction understanding, buffer state recognition, pulse output and pulse output state monitoring.

The image acquisition unit includes a right-angle prism, three cameras, three LEDs and a network switch; the three cameras are respectively located on the left, right and rear sides of the Y waveguide chip, and are placed horizontally, and are respectively marked as left camera, The right camera and the rear camera; three LEDs illuminate the input end, the front output end and the rear output end obliquely at a direction angle of 30 degrees to the optical fiber axis; Image transfer between a camera and a desktop computer;

In the image acquisition unit, when the three LEDs are turned on, the left camera collects the end face images of the front output end and the rear output end, the right camera collects the end face images of the input end and the upper edge image of the light exit point of the Y waveguide chip, and when the three LEDs are turned off , when the red light source is turned on, the right camera captures the images of the front light-emitting point and the rear light-emitting point of the Y waveguide chip. Driven by the three-dimensional electric platform, the rear camera collects the rear view images of the input terminal, the Y waveguide chip, the front output terminal and the rear output terminal, and the top view image reflected by the rectangular prism.

The image processing and control unit includes a computer and a direct coupling program. The computer is connected with three cameras, an optical power meter and a motion controller. The direct coupling program includes: extracting the three-dimensional angle and the three-dimensional position of the Y-waveguide chip, the input terminal, the front output terminal and the rear output terminal, and outputting the commands for controlling the motion of the three six-dimensional electric stages to the motion controller; After adjusting the attitude of the input terminal, front output terminal and rear output terminal, adjust the input terminal, front output terminal and rear output terminal according to the measurement value of the optical power meter to obtain the final coupling point.

The image processing and control unit uses the image processing method to complete the three-dimensional angle adjustment and left-right position adjustment of the input end, the front output end, and the rear output end, and the preliminary adjustment of the up-down position and the front-back position; The order from top to bottom is within the rectangular box with a side length of 6um. Adjust the input terminal, front output terminal and rear output terminal in sequence with a step distance of 50nm, and find the corresponding input terminal, front output terminal and rear output terminal when the power value is the largest. position, as the final coupling point.

Compared with prior art, advantage and positive effect of the present invention are:

(1) The Y waveguide chip automatic direct coupling device based on image recognition and optical power feedback provided by the present invention avoids two welding points inside the fiber optic gyroscope, simplifies the manufacturing process of the fiber optic gyroscope, and improves the mechanical properties of the optical fiber inside the fiber optic gyroscope; Avoid the influence of back reflection and polarization crosstalk introduced by fiber fusion on the measurement accuracy of fiber optic gyroscope; at the same time, improve the life and quality of fiber optic gyroscope.

(2) The present invention adopts the image processing method to obtain the six-dimensional pose information of the optical fiber and the Y waveguide chip, and reasonably selects the optical magnifying lens, so that the device can meet the measurement accuracy requirements, realize the precise alignment of the optical fiber and the Y waveguide chip, and have a large enough The measurement range reduces the device's requirements for the initial installation accuracy of the optical fiber. The device adopts the four angles of view of the rear camera overlooking the image, the rear view image, the left camera image, and the right camera image to recognize the posture, and the use of information redundancy improves the robustness of the device operation.

(3) The present invention utilizes two output terminals and the Y waveguide chip to form a loop, and the optical power meter is placed at the return end of the circulator to monitor the change of the optical power, which solves the problem that there is no monitoring point between the Y waveguide chip and the optical fiber ring. The optical power value can independently and accurately adjust the up and down positions of the input terminal, front output terminal and rear output terminal to ensure the coupling quality.

(4) The present invention installs a right-angle prism on the bottom surface of the top cover of the Y-waveguide chip. By adjusting the up and down positions of the rear camera, it is independently selected whether to select the right-angle prism to switch the camera angle of view, realizing the function of one camera observing the rear view and the top view, and reducing the number of cameras. The volume of the direct coupling device is reduced, and the cost is reduced at the same time.

(5) The present invention uses PLC as motion controller, and anti-electromagnetic interference is strong, makes the direct coupling operation of device more stable; Adopts time-division multiplexing technology to utilize PLC six-way pulse interface to realize 24 axis motor control, has avoided the use of a plurality of PLCs, The volume of the direct coupling device is saved.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the Y-waveguide chip automatic direct coupling device based on image recognition and optical power feedback in the present invention;

Fig. 2 is the step-by-step ladder program flow chart of the motion controller in the motion execution unit in the present invention;

3 is a schematic diagram of image features to be extracted for image recognition in the image processing and control unit of the present invention;

Fig. 4 is the flow chart of straight line feature extraction algorithm in image processing and control unit in the present invention;

Fig. 5 is a flow chart of the circular feature extraction algorithm in the image processing and control unit of the present invention.

In the picture:

1-broad-spectrum light source; 2-red light source; 3-first circulator; 4-second circulator; 5-input terminal; 6-Y waveguide chip;

7-front output port; 8-rear output port; 9-fiber ring; 10-rectangular prism; 11-left camera; 12-right camera; 13-rear camera;

14-the first LED; 15-the second LED; 16-the third LED; 17-the first six-dimensional electric platform; 18-the second six-dimensional electric platform;

19-Third and six-dimensional electric stage; 20-One-dimensional electric stage; 21-Two-dimensional electric stage; 22-Three-dimensional electric stage; 23-Y waveguide fixing mechanism;

24-motion controller; 25-desktop computer; 26-optical power meter; 27-network switch.

Detailed ways

The present invention will be further described in detail with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , the present invention provides a direct coupling device between a Y-waveguide chip and a polarization-maintaining fiber ring, including: an optical path unit, an image acquisition unit, a motion execution unit, an image processing and control unit, and a human-computer interaction unit.

The optical path unit includes a wide-spectrum light source (SLD) 1, a red light source 2, a first circulator 3, a second circulator 4, an input end 5, a Y waveguide chip 6, a front output end 7, a rear output end 8 and an optical fiber ring 9 , for implementing the action object of the present invention. The optical path unit also includes an optical power meter 26 . The first circulator 3 and the second circulator 4 include a circulator input end, an output end and a return end. The wide-spectrum light source 1 is connected to the input end of the first circulator 3, and the red light source 2 is connected to the return end of the first circulator 3. The application of the first circulator 3 can realize online switching between the wide-spectrum light source 1 and the red light source 2. The input end of the second circulator 4 is connected to the output end of the first circulator 3 , and the output end is connected to the input end 5 . The input end 5 is an optical fiber pigtail with a small piece of lithium niobate, the front output end 7 and the rear output end 8 are respectively the two ends of the optical fiber ring 9, and the pigtails at both ends are respectively bonded to the lithium niobate small piece. on the block. The purpose of the present invention is to adjust the positions of the input terminal 5, the front output terminal 7 and the rear output terminal 8 to realize precise coupling with the light entrance point, the front light exit point and the rear light exit point of the Y waveguide chip 6. In the optical path unit of the device of the present invention, the optical power meter 26 is connected to the return end of the second circulator 4 for measuring the optical power returned by the input end 5 .

The motion execution unit includes a first six-dimensional electric stage 17, a second six-dimensional electric stage 18, a third six-dimensional electric stage 19, a one-dimensional electric stage 20, a two-dimensional electric stage 21, a three-dimensional electric stage 22, and a Y waveguide fixing mechanism 23 and a motion controller 24 . The Y waveguide fixing mechanism 23 is used to fix the Y waveguide chip 6, the one-dimensional motorized stage 20 realizes the focus of the left camera 11, the two-dimensional motorized stage 21 realizes the focus and X-axis translation of the right camera 12, and the three-dimensional motorized stage 22 realizes the three-dimensional position of the rear camera 13 control. An optical fiber clamp is installed on the first six-dimensional electric table 17 to clamp the input end 5 to control the six-dimensional posture of the input end 5, and an optical fiber clamp is installed on the second six-dimensional electric table 18 to clamp the front output end 7 to control the front output end 7. For the six-dimensional attitude, an optical fiber clamp is installed on the third six-dimensional electric platform 19 to clamp the rear output end 8 to control the six-dimensional attitude of the rear output end 8 . The motion controller 24 sends to the displacement platforms of the one-dimensional electric stage 20, the two-dimensional electric stage 21, the three-dimensional electric stage 22, the first six-dimensional electric stage 17, the second six-dimensional electric stage 18 and the third six-dimensional electric stage 19. Attitude control signal.

The motion controller 24 includes a programmable logic controller (PLC) and a step ladder program. The stepping trapezoidal program includes image processing and the attitude adjustment instruction reception sent by the control unit, the pulse output required for the movement control of the displacement platform, and the feedback of the pulse output state. The motion controller 24 uses time-division multiplexing technology to divide the 24-axis motor control into four groups, and each group controls six dimensions. According to the functional requirements, the simultaneous adjustment of the translation stage is planned as a group. The first group includes the erection of the left camera. The one-dimensional electric platform 20 of the right camera, the two-dimensional electric platform 21 of the right camera, the three-dimensional electric platform 22 of the rear camera; the second group is the first six-dimensional electric platform 17 for controlling the posture of the input terminal 5; the third group is for controlling the front The second six-dimensional electric stage 18 of the output end 7; the fourth group is the third six-dimensional electric stage 19 of the output end 8 after control. Moreover, the use of time-division multiplexing technology effectively reduces the demand for the pulse output interface of the motion controller 24 and effectively reduces the volume of the motion controller 24 . The stepping ladder program includes instruction receiving, instruction understanding, buffer state recognition, pulse output and pulse output state monitoring. As shown in Figure 2, the PLC first initializes command reception, sets the command receiving buffer, and allows receiving; after receiving a set of commands, store them in the receiving buffer, read a set of commands from the receiving buffer, understand the command, and output The corresponding number of pulses controls the movement of the corresponding translation platform, monitors the pulse output status, and when the output is completed, continue to read the next set of instructions from the receiving buffer. When the receiving buffer is full, the PLC sends a signal to the computer 25 to suspend data transmission.

The image acquisition unit includes a rectangular prism 10 , a left camera 11 , a right camera 12 , a rear camera 13 , a first LED (light emitting diode) 14 , a second LED 15 , a third LED 16 and a network switch 27 . The network switch 27 is used to expand the network interface to realize image transmission between the left camera 11 , the right camera 12 , the rear camera 13 and the desktop computer 25 . The left camera 11 and the right camera 12 use a high-resolution CCD (charge-coupled device) camera to extract the end face of the input end 5, the end face of the front output end 7 and the end face of the rear output end 8. The rear camera 13 adopts a high resolution CMOS (Complementary Metal Oxide Semiconductor) camera. The rectangular prism 10 is mounted on the bottom surface of the upper cover of the Y waveguide fixing mechanism 23 . The first LED14 irradiates the input end 5 at an angle of 30 degrees to the axis of the fiber, the second LED15 irradiates the front output end 7 at an angle of 30 degrees to the axis of the fiber, and the third LED16 irradiates the output end 7 at an angle of 30 degrees to the axis of the fiber. Output terminal 8 after irradiation. Turn on the three LEDs 14, 15, 16, and the left camera 11 collects the end face images of the front output end 7 and the rear output end 8, and collects the left view of the front output end 7. The image is shown in the enlarged area in Figure 3, and the obtained rear Left view of output 8. The right camera 12 collects the end face image of the input end 5, and acquires the right view of the input end 5 and the upper edge image of the light exit point of the Y waveguide chip. Turn off the three LEDs 14, 15, 16, turn on the red light source 2, and the right camera 12 collects the images of the front light-emitting point and the rear light-emitting point of the Y waveguide chip 6. The rear camera 13 has its own light source, and no additional light source needs to be added. Driven by the three-dimensional electric stage 22, the rear camera 13 moves up to a suitable height, and simultaneously adjusts the other two dimensions of the three-dimensional electric stage 22 to collect the input end 5, the Y waveguide chip 6, the front output end 7, For the top-view image of the rear output terminal 8, move the rear camera 13 down to a suitable height, adjust the other two dimensions of the three-dimensional translation stage 22 at the same time, and collect the rear images of the input terminal 5, the Y waveguide chip 6, the front output terminal 7, and the rear output terminal 8. Visual image.

The image processing and control unit includes a desktop computer 25 and a directly coupled program on the computer 25 . Send a signal to the control motion controller 24 according to the coupling state to realize the one-dimensional electric table 20, the two-dimensional electric table 21, the three-dimensional electric table 22, the first six-dimensional electric table 17, the second six-dimensional electric table 18, and the third Control of the six-dimensional electric platform 19. A desktop computer 25 is connected to three cameras 11 , 12 , 13 , an optical power meter 26 and a motion controller 24 . The direct coupling program includes: extract the three-dimensional angle information program of the Y waveguide chip, input end, front output end and rear output end, the three-dimensional angles are pitch angle, yaw angle and polarization angle; extract the Y waveguide chip, input end, front output end and The three-dimensional position information program of the rear output end; output the command to control the movement of the three six-dimensional electric stages to the motion controller; after adjusting the attitude of the input end, front output end and rear output end using the image collected by the camera, according to the optical power meter The measured value precisely adjusts the front, back, up and down positions of the input terminal, the front output terminal and the rear output terminal to obtain the final coupling point.

The desktop computer 25 collects the image information of the left camera 11 , the right camera 12 , and the rear camera 13 , and recognizes image features, as shown in FIG. 3 , and executes a direct coupling program. Use the image collected by the right camera 12 to identify the input end face fiber core, polarization axis, and Y waveguide chip 6 polarization angles. After the polarization angle identification is completed, control the first six-dimensional electric stage 17 to rotate the optical fiber to reduce the input end 5 polarization angles and The angle difference of the polarization angle of the Y waveguide chip 6 . Use the image collected by the left camera 11 to identify the coordinates and polarization angle of the fiber core at the front output end 7, and the fiber core coordinates and polarization angle at the rear output end 8. After the polarization angle identification is completed, combine the polarization of the Y waveguide chip identified by the right camera 12 Angle information, rotate the optical fiber by the second six-dimensional electric stage 18 or the third six-dimensional electric stage 19, reduce the angle difference of the polarization angle of the front output end 7 and the Y waveguide chip 6, reduce the rear output end 8 and the Y waveguide chip The angular difference of the polarization angle of 6. Use the image collected by the rear camera 13 to identify the upper edge angle of the input end, the upper edge angle of the light incident point, the side edge angle of the input end, and the side edge angle of the light input point, and control the yaw and pitch of the input end 5 according to the obtained angle difference. Similarly, use the image collected by the rear camera 13 to identify the upper edge angle of the front output end, the upper edge angle of the light output point, the side edge angle of the front output end, and the side edge angle of the light output point, and adjust the deflection of the front output end 7 according to the obtained angle difference and pitch. Use the image collected by the rear camera 13 to identify the upper edge angle of the rear output end, the upper edge angle of the light-emitting point, the side edge angle of the rear output end, and the side edge angle of the light-emitting point, and adjust the yaw and pitch of the rear output end 8 according to the obtained angle difference. Utilize the image collected by the rear camera 13 to identify the coordinates of the light incident point of the Y waveguide chip 6 and the coordinates of the apex on the side edge of the light incident point, and comprehensively obtain the three-dimensional coordinate information of the light incident point of the Y waveguide chip. Calculate the coupling point at the input end, and combine the fiber core information of the input end 5 collected by the right camera 12 to obtain the three-dimensional coordinates of the coupling point at the input end 5, and calculate the three-dimensional position deviation from the incident point of the Y waveguide chip 6 to adjust the three-dimensional position of the input end 5 panning. After the adjustment of the input terminal 5 is completed, turn on the red light source 2, observe the upper edge of the light emitting point of the Y waveguide chip with the right camera 12, collect the images of the front light emitting point and the rear light emitting point of the Y waveguide chip 6, and determine the front light emitting point and the rear light emitting point according to the image information The upper, lower, and front and rear positions of the point are collected by the rear camera 13 on the upper edge of the light-emitting point of the Y waveguide chip 6, and the three-dimensional coordinates of the front and rear light-emitting points of the Y-waveguide chip 6 are obtained comprehensively; The coupling point of the front output end, combined with the information of the 7 fiber cores of the front output end collected by the left camera 11, obtains the three-dimensional coordinates of the coupling point of the front output end 7, and calculates the three-dimensional position deviation from the front output point of the Y waveguide chip 6, thereby adjusting the front output end 7 three-dimensional translation. Similarly, the three-dimensional displacement of the output terminal 8 is adjusted.

The upper, lower, front and rear coordinate accuracy of the coupling points of the input terminal 5, the front output terminal 7, and the rear output terminal 8 provided by the above-mentioned image recognition cannot meet the requirements of direct coupling accuracy. The device of the present invention further fine-tunes according to the light intensity of the optical power meter 26. Turn on the wide-spectrum light source 1, and finely adjust the up, down, front and back positions of the input terminal 5, the front output terminal 7 and the rear output terminal 8 by the output power of the optical power meter 26. According to the sequence from front to back and from top to bottom, adjust the input terminal 5, the front output terminal 7 and the rear output terminal 8 sequentially with a step distance of 50nm in the rectangular frame with a side length of 6um, and record the optical power meter 26 by the desktop computer 25 at the same time Power level, find the position information of input terminal 5, front output terminal 7 and rear output terminal 8 corresponding to the maximum power value, move input terminal 5, front output terminal 7 and rear output terminal 8 to the maximum power position, and solidify the coupling point , the automatic direct coupling process ends.

The top view and rear view of the input terminal 5, the front output terminal 7, the rear output terminal 8 and the Y waveguide chip 6 collected by the rear camera 13 in the above direct coupling program, and the input terminal 5, the front output terminal 7 and the rear output terminal obtained therefrom The upper edge angle, the side edge angle, the three-dimensional coordinates of the end 8 and the upper edge angle of the light incident point of the Y waveguide chip 6, the side edge angle of the light input point, the upper edge angle of the light exit point, the side edge angle of the light exit point, and the polarization angle of the Y waveguide chip 6 The essence of extraction is straight line feature recognition, and the coordinate extraction actually extracts the intersection points of straight lines. The recognition of the three-dimensional coordinates and polarization angles of the input end 5, the front output end 7, and the rear output end 8 is essentially circular feature recognition.

The input image for the above straight line feature extraction has the following characteristics: one image has one straight line, two straight lines or multiple straight lines; when there are multiple straight lines, their relative orientation is fixed; the angle of the straight line changes very little, but the position of the straight line changes relatively big. In order to improve the robustness of the device, the self-adaptive sliding window method is adopted in the direct coupling program of the present invention, as shown in Figure 4, specifically: setting the initial value of the window size and the sliding window step distance, sliding the window, and cutting to obtain sub-images , use the Candy operator to extract the edge of the sub-image, use the iterative least squares method to fit the straight line equation, the straight line that meets the angle limit condition will be output, if the expected straight line cannot be found in the limited number of cycles, change the window size and sliding window step distance, and search for the straight line again. The invention adopts the sliding window method to extract the straight line feature according to the image feature, and adopts the least square method of iterative fitting to optimize the straight line edge, so as to realize the extraction of multi-objective and high-precision in the image.

Aiming at the characteristic that the image of the optical fiber end face is relatively noisy, the present invention adopts a random circle detection algorithm with strong anti-interference to extract the coordinates of the fiber core and the contours of two panda eyes. As shown in Figure 5, the computer 25 reads in a frame of image collected by the camera, first uses the Canny operator to extract the edge of the image, then randomly selects 4 points from the edge image, uses 3 of them to construct a circle, and verifies the fourth point Whether the point is on the three constructed circles, if not, resample; if yes, then verify the number of points on the construction circle among the remaining edge points, if the number of points meets the limiting conditions, then the construction circle is True circle, otherwise resample. After three circles are detected from the image, the center of the circle with the largest radius is taken as the fiber core coordinates, and the line connecting the two small circles is taken as the polarization angle. The invention adopts a random circle detection algorithm to extract the coordinates of the fiber core and the polarization angle, and is stronger in anti-interference than the traditional Hough transform.

Subsequently, the human-computer interaction unit includes a desktop computer 25 and a user operation interface. The interface accepts input from the operator's keyboard and mouse events, controls the operation process of the direct coupling device, displays the camera image and optical power in real time, and realizes automatic direct coupling to the Y waveguide chip. On-line monitoring of control and coupling quality.

Claims (9)

1. a kind of automatic direct-coupling device of Y waveguide chip based on image recognition and optical power feedback, which is characterized in that including Optical path unit, image acquisition units, Motor execution unit and image procossing and control unit；

Including Y waveguide chip to be coupled, input terminal, preceding output end, rear output end and fiber optic loop in the optical path unit, and The optical power size that light power meter measurement input terminal returns is set；

The Motor execution unit includes：For fixing the Y waveguide fixed mechanism of Y waveguide chip, the one-dimensional of left camera is set up Motorized stage sets up the two-dimentional motorized stage of right camera, the three-D electric platform of camera after erection, respectively control signal, preceding output end With the three sextuple motorized stages and motion controller of rear output end posture；Motion controller is electronic to one-dimensional motorized stage, two dimension The sextuple motorized stage of platform, three-D electric platform and three sends attitude control signal；

The image acquisition units include right-angle prism, three cameras, three Light-emitting diode LED and the network switch；Three A camera is located at the left side, right side and rear side of Y waveguide chip, and horizontal positioned, is respectively labeled as left camera, right phase Machine and rear camera；Three LED respectively with shaft axis of optic fibre at 30 degree of deflection oblique illumination input terminals, preceding output end and rear output End；Right-angle prism is installed on the upper cover bottom surface of Y waveguide fixed mechanism；The network switch for three cameras and desktop computer it Between image transmitting；

The image procossing and control unit includes computer and direct-coupling program；The computer connects three phases Machine, light power meter and motion controller；The direct-coupling program includes：Extract Y waveguide chip, input terminal, preceding output end With the three-dimensional perspective and three-dimensional position of rear output end, the instruction for controlling three sextuple motorized stage movements is exported to motion control Device；After the posture using the Image Adjusting input terminal of camera acquisition, preceding output end and rear output end, according to the survey of light power meter Magnitude adjusts input terminal, preceding output end and rear output end and obtains final Coupling point.

2. the automatic direct-coupling device of Y waveguide chip according to claim 1, which is characterized in that the optical path unit Including wide spectrum light source, red-light source, first annular device, the second circulator, input terminal, Y waveguide chip, preceding output end, rear output End, fiber optic loop and light power meter；Wide spectrum light source is connected with the input terminal of first annular device, and red-light source is returned with first annular device End is gone back to be connected；The input terminal of second circulator connects the output end of first annular device, and input terminal is connected to the defeated of the second circulator Outlet；Light power meter is connected to the return terminal of the second circulator.

3. the automatic direct-coupling device of Y waveguide chip according to claim 1, which is characterized in that the motion control Device includes programmable logic controller (PLC) and stepping trapezoid program；Motion controller uses time-sharing multiplexing technology, by 6 motorized stages 24 spindle motors are divided into four groups, and 6 dimensions of every group of control control 6 dimensions using 6 road pulse interfaces of programmable logic controller (PLC) Degree；Stepping trapezoid program includes the reception of instruction, the understanding of instruction, buffer state identification, pulse output and pulse output shape State monitoring.

4. the automatic direct-coupling device of Y waveguide chip according to claim 1, which is characterized in that the Image Acquisition Unit, when opening three LED, left camera acquires the end face figure like of preceding output end and rear output end, and right camera acquires input terminal End face figure like and Y waveguide chip go out rib image on luminous point, closing three LED, when opening red-light source, right camera acquisition The preceding luminous point out of Y waveguide chip and rear dot pattern picture out；The rear camera is under the drive of three-D electric platform, acquisition input End, the backsight image of Y waveguide chip, preceding output end and rear output end and the top view image by right-angle prism reflection.

5. the automatic direct-coupling device of Y waveguide chip according to claim 1 or 4, which is characterized in that at the image Reason and the direct-coupling program in control unit, Image Adjusting input terminal, preceding output end and the rear output end acquired using camera Posture, specifically include：

Image recognition input terminal end face fiber core, polarization axle and the Y waveguide chip angle of polarization acquired using right camera, control clamping are defeated Enter the sextuple motorized stage spin fiber at end, reduces the differential seat angle of the input terminal angle of polarization and the Y waveguide chip angle of polarization；

Utilize output end end face fiber core coordinate and the angle of polarization before the image recognition of left camera acquisition, and rear output end end face fiber core Coordinate and the angle of polarization, the Y waveguide chip identified in conjunction with right camera polarize angle information, and control clamps preceding output end or rear output end Sextuple motorized stage spin fiber, the differential seat angle of the angle of polarization of output end and Y waveguide chip before reducing, output end and Y wave after reduction Lead the differential seat angle of the angle of polarization of chip；

Enter to hold upper angularity using the image recognition of rear camera acquisition, enter angularity on luminous point, enter end side angularity and enter luminous point Incline angle adjusts beat and the pitching of input terminal；Utilize angularity, out luminous point in outlet before the image recognition of rear camera acquisition Upper angularity, preceding outlet incline angle and luminous point incline angle out, the beat of output end and pitching before adjusting；It is adopted using rear camera Angularity in outlet after the image recognition of collection goes out angularity on luminous point, rear outlet incline angle and luminous point incline angle out, adjustment The beat of output end and pitching afterwards；

Enter luminous point coordinate using the image recognition Y waveguide chip that rear camera acquires and enter apex coordinate on luminous point incline, obtains Y wave It leads chip and enters luminous point three-dimensional coordinate, according to rib, incline on input terminal, resolve input terminal Coupling point, acquired in conjunction with right camera defeated Enter to hold fibre core information, obtain the three-dimensional coordinate of input terminal Coupling point, calculates and Y waveguide chip enters light spot position deviation, with adjustment Input terminal D translation；

After the completion of input terminal adjustment, red-light source is opened, go out luminous point before acquiring Y waveguide chip by right camera and goes out dot pattern afterwards Picture, go out before being determined according to image luminous point and it is rear go out luminous point up and down, front-rear position, Y waveguide chip light-emitting point is acquired by rear camera Upper rib, the comprehensive three-dimensional coordinate for obtaining going out luminous point before Y waveguide chip, going out luminous point afterwards；According to rib, incline on preceding output end, resolve Preceding output end Coupling point, and the preceding output end fibre core information of left camera acquisition is combined, the three-dimensional of output end Coupling point is sat before obtaining Mark goes out luminous point three-dimensional position deviation before calculating and Y waveguide chip, output end D translation before adjusting；Similarly, output end after adjustment Three-D displacement.

6. the automatic direct-coupling device of Y waveguide chip according to claim 5, which is characterized in that the direct-coupling Program, upper angularity, incline angle, three-dimensional coordinate and the Y waveguide chip for extracting input terminal, preceding output end and rear output end enter light Angularity, the angle of polarization enter luminous point incline angle, go out angularity on luminous point, going out luminous point incline angle and Y waveguide chip on point, It is using extraction of straight line method；The extraction of straight line method utilizes the minimum of iteration using adaptive sliding window method Square law fitting a straight line equation.

7. the automatic direct-coupling device of Y waveguide chip according to claim 5, which is characterized in that the direct-coupling Program extracts the three-dimensional coordinate and polarization angle of input terminal, preceding output end, rear output end, is using circular feature extracting method； The circular feature extracting method is random loop truss algorithm.

8. the automatic direct-coupling device of Y waveguide chip according to claim 1, which is characterized in that the computer root It is walked according to light power meter output power size according to sequence from front to back, from top to bottom in side length 6um rectangle frame with 50nm Away from input terminal, preceding output end and rear output end is successively adjusted, find corresponding input terminal when magnitude of power maximum, preceding output end and The position of output end afterwards, as final Coupling point.

9. the automatic direct-coupling device of Y waveguide chip according to claim 1, which is characterized in that the device also wraps Man-machine interaction unit is included, for the operational sequence of user's control direct-coupling device, real-time display camera image and optical power are big It is small, coupling mass is monitored on-line.